Dynamo-electric machine



(No Model.)

' T. H. HICKS.

DYNAMO ELECTRIC MACHINE. No. 543,383. Patented July 23, 1895.

IVHWESSES 4 lm Em'm V z m4 By $9 242207722] I UNITED STATES PATENTOFFICE.

THOMAS H. HICKS, OF DETROIT, MICHIGAN.

DYNAMO-ELECTRIC MACHINE.

SPECIFICATION forming part of Letters Patent No. 543,383, dated July 23,1 895.

Application filed January 13, 1894:- Serial No. 496,756. (No model.)

.To aZZ whom it may concern:

Be it known that I, THOMAS H. HIcKs, a subject of the Queen of GreatBritain, residing at Detroit, county of Wayne, State of Michigan, haveinvented a certain new and useful Improvement in a Radial Consequent-Pole Electric Machine; and I declare the following to be a full, clear,and exact description of the invention, such as will enable othersskilled in the art to which it appertains to make and use the same,reference being had to the accompanying drawings, which form a part ofthis specification.

This invention relates to certain new and useful improvements in radialconsequentpole dynamoelectric machines. Said improvements referspecifically to the construction and arrangement of the field-magnetsand the construction of the commutator used in connection therewith.

The two parts of my invention-via, the field-magnets and thecommutator-I have illustrated separately, Figures 1, 2, and 3 referringto the field-magnets,'and Figs. 4, 5, and 6 to the commutator.

In the drawings, Fig. 1 is an end elevation showing all parts of myinvention which refer to the field-magnets. Fig. 2 is a view inperspective of the magnet-cores upon which the field-coils are to bewound. Fig. 3 is a longitudinal section of the commutator. Fig. 4 is anend view of the commutator, serving to represent either end through thelines a: so of Fig. 3. Fig. 5 is a side elevation showing the externalparts of a complete commutator except the cement R, which is omitted soas to expose the wire band L.

The field-magnet portion of my invention I describe as follows: Thefield-magnet consists of two radial cores or limbs B and B, joined to atriangular pole-piece O. The two magnet-limbs are secured to yokes F F.The limbs B and B are each wound with ordinary bobbins of wire D D,which are joined together in any well-known manner, so that when acurrent of electricity flows through the two bobbins or helices D D likepolarities of one magnetic sign will be set up in the triangularpole-piece O and the opposite poles of the other polarity set up in theyokes F F. Each magnet-limb is wound with a helix or bobbin of wire, thehelix of one limb being marked D and the helix of the other limb beingmarked D. T is a space which separates the ends of the yokes.

The dotted lines P P in Fig. l indicate the axes of the two magnet-limbsB B, and the dotted line P indicates the magnetic axis between the twofield-poles of opposite polarities, one of said poles being marked withdashes (thus, and the other by crosses (thus,

My chief object in constructing the fieldmagnet of two radial limbs andforming one polein the yokes is to shorten the return magnetic circuitthrough the yokes. If a magnet having only one limb were used instead ofthe one I have described, its length would require to equal the totallength of the two limbs I show. In such a case the outerend of theone-limb magnet would be located at W, Fig. 1,the magnetic circuit beingthereby increased the extra distance, which I indicate by the dottedlines which start from the point W and terminate in the outer ends ofthe dotted lines P P, representing the axes of the two limbs B B. Abiradial magnet of itself is not new; but a biradial magnet having oneof the polepieces located in the yokes and the space T, which preventsmagnetic leakage from the pole-piece C to the outer ends of the magnets,forms a new combination.

G2 in Figs. 1, 2, 3, 4, and 5 indicates a shaft. The commutator isconstructed as follows: I take a sleeve G, Figs. 3 and 4:, which may beof iron, and I cover this sleeve with an insulating-band H, upon whichthe commutatorsegments J are arranged and pressed firmly around theinsulation by a powerful annular clamp, which is only used duringconstruction, and hence is not shown in the drawings. The segments ofthe commutator thus held together are then turned off in a lathe,forming sunken portions of the segments at the end peripheries, and alsoin a portion of the segments corresponding to portions of the commutatorcoming between each pair of brushes used. The sunken portions of theends referred to are marked K, and the portion between the brushes ismarked K Figs. 6 and 8. These sunken portions, which form annulargrooves, are next insulated at the bottom and sides, and each one isthen wound with a band of strong wire. The convolutions of said wire arethen soldered together, and the end bands are then turned off in thelathe. The bands of wire are marked L. A metal ring M is next turned offin the lathe, so that its inner surface will just pass over the wirebands L when strong force is applied. The central band or bands do notrequire an outer ring M. hVhen the commutator is thus far constructed,the annular clamp above referred to is next removed and the commutatorcan then be turned off on the periphery surface and ends. I next putinsulating-disks of asbestos at the ends of the commutator over thesleeve and then screw a nut at each end of the sleeve against theasbestos. The nuts are marked N and the asbestos O. The nuts are onlyused for protection to the ends of the segments and for appearance. Theydo not assist in holding the commutator together, the rings M and thebands L being alone used for that purpose.

My objectin using a spongy substance, such as asbestos O, is to allowstill further com pression thereof when the segments of the commutatorexpand in length by heat during rotation. In this way expansion of thesegments does not affect the integrity of the commutator. The band L isto prevent the segments from rising in their center during expansion androtation, which is sure to occur when long segments are used and whenonly held together from their ends alone. After the wire band L is woundin the annular groove K, I then fill each groove on the top of the bandwith a suitable cement, such as plaster-of-paris. \Vhen the cement, isturned off even with the segments of the commutator it maybe shellacked.The cement is marked R and is shown in section in Fig. 6. When verylargecommutators are to be made, I then prefer to widen the base of thegroove K, so as to form a slight dovetail. This I do to more securelyprevent the plaster-of-paris from coming out of the groove; but it isvery diffioult to get it out of the grooves even when its sides areparallel to each other. The cement prevents all metallic dust fromshort-circuiting the commutator-segments and adds to the appearancealso.

When carbon brushes are used it becomes necessary that the comutatorshould preserve its external shape while hot and during rotation.Otherwise, heat and sparking at the brushes would occur to a detrimentalextent. A commutator constructed in a manner such as I have describedprevents the segments from either sinking or rising, the sleeve abovedescribed preventing them from sinking and the wire bands and metalrings preventing them from rising.

My object in using a wire band L under the metal ringM'is to prevent thering from either wrinkling, tearing, or moving the insulation which isunder the band. It would be impossible to obtain sufficient pressure bythe ring alone if pressed over the insulation without the wire bands.Instead of pressing the rings over the wire bands the former may bescrewed on, using the wire as a thread and then threading the ring tomatch the wire; but such a method would be more trouble to carry intopractice. \Vhen only one pair of brushes is used the groove K and itswire band L may be omitted, this band only becoming necessary when thecom inutator-segments are beyond a length required for one pair ofbrushes.

\Vhat I claim as my invention is- 1. In an electric machine, a fieldmagnet consisting of two radial limbs B and B, a polepiece 0 of onemagnetic polarity joining said limbs together at one end, separate yokesF and F joining the other ends of said limbs, the ends of the yokes,joined to the magnetliinbs, being separated by a space T; the magneticpolarities of the outer ends of the magnet-limbs, established in theyokes, having an opposite polarity to the pole-piece O, substantially asdescribed.

2. In an electric machine, the combination with yokes, F and F, of afield magnet having only two radial limbs, B and B: said yokes havinglocated therein one of the field poles, substantially as described.

3. In an electric machine, the combination with yokes F and F, separatedfrom each other at one end by the space T, of a field magnet havingradial limbs B and B, and having one of the magnetic field-poles locatedin said yokes, substantially as described.

4.. In an electric machine, the combination with yokes F and F, of afield magnet having only two radial limbs 13 and B; said yokes beingseparated at one end by the space T; magnetic poles of one polaritybeing located in said yokes, substantially as described.

5. In an electric machine, the combination of yokes F and F, with fieldmagnets each consisting of radial limbs B and B, and a pole-piece O; theyokes each being bolted to one of the outer ends of the radial limbs;each pair of yokes and radial limbs beingseparated at their ends by anopen space T, substantially as described.

6. In an electric machine, the combination of two field magnets eachhaving two radial limbs 13 and B, and a pole-piece C; of the yokes F andF uniting said field -magnets, only one of said yokes being secured tothe base of the machine; the ends of the yokes being separated from eachother by an open space between each pair of radial limbs B and Bsubstantially as described.

'7. In an electric machine provided with field magnets, an armature,armature shaft, and a commutator, the commutator constructed with asleeve, G, mounted on the armature shaft, commutator segments insulatedfrom the sleeve, said segments of said commutator constructed withannular grooves located at the peripheral ends of the segments; wirebands, L, located in said grooves and insulated from the segments, andrings located upon said wire bands, substantially as described.

8. In an electric machine provided with field magnets, an armature,armature shaft, and a commutator, the commutator con structed with asleeve, G, mounted on the armature shaft, segments insulated from thesleeve, the segments of said commutator constructed with annular grooveslocated at the peripheral ends of the segments; an annular grooveintermediate the ends of said commutator, wire bands located in each ofsaid grooves, the intermediate wire band preventing the commutatorsegments from rising in the center during the rotation of the armature,substantially as described.

9. In an electric machine, a commutator constructed with an annulargroove, K, and a wire band located in said groove to prevent thecommutator segments from rising during the rotation of said commutator,substantially as described.

10. In an electric machine, a commutator constructed with an annulargroove, K, a wire band located in said groove to prevent the commutatorsegments from rising during the rotation of said commutator, and acovering cement located upon said wireband, substantially as set forth.

11. In an electric machine, a commutator constructed with annulargrooves, K, toward the extremities of the commutator, wire bands locatedin said grooves and insulated from the commutator segments,substantially as described.

12. In an electric machine, a commutator constructed with annulargrooves, K, toward the extremities of the commutator, wire bands locatedin said grooves and insulated from the commutator segments, and ringslocated THOMAS H. HICKS. Witnesses:

N. S. WRIGHT,

OTTO B. BARNZIGER.

